Sunday, November 27, 2011

VISIT TO “KRILL CITY” IN FLANDERS BAY

Our last stop on our Salp Survey cruise was to Flanders Bay, a protected fjord off Gerlache Strait. We couldn’t have been luckier with the weather! The morning of Nov. 25th was sunny and calm, offering a stunning landscape of snow-covered peaks and glaciers and their reflected images in the still waters (Fig. 1).

Figure 1. View with reflections in the calm waters of Flanders Bay, Western Antarctic Peninsula region.

The good weather was particularly welcome since we had planned two launch two small boats from the LM Gould: one for salp and krill collection and the other for a small-scale bioacoustic survey. Both Zodiacs followed the ship’s trail through the ice (Fig. 2) to get closer to an area that Joe Warren had studied last year and dubbed “Krill City”. One zodiac was equipped for a small-scale bioacoustical survey of zooplankton distributions.

Figure 2. Left: The LM Gould clearing a path through the ice in Flanders
Bay for the small boat operations. Right: Joe Warren standing in a
zodiac equipped for small-scale bioacoustical surveys of zooplankton
distribution and abundance.

The second zodiac was launched with a team to collect salps and krill. Our scientific pursuits did not at all interfere with the fund and adventure of being on the water in a stunning landscape of snow and ice and sparkling clear water (Fig. 3).

Figure 3. Small boat operations in Flanders Bay. A) The acoustics
survey team included Kelley Watson (MT and Zodiac driver) and Katy
Wurtzell. B) The salp- and krill-collecting team included MST Melissa
Paddock (left) and MT Krista Tyburski (B) and Paola Batta-Lona (C). D)
Krista at the helm.

As we navigated around bergy-bits and ice-flows, we came across wildlife that seems unconcerned by such strange orange beings (the float coats are required for on-the-water work, so everyone is very similarly attired). We heard a minke whale come up for air and were surrounded by penguins who kept a watchful eye of us, but stood their ground (Fig 4).

Figure 4. Gentoo penguins were everywhere in the Bay. They hung out on
the ice and stood up to keep an eye on us.We also saw them porpoising
through the water, including one who followed our zodiac for several
minutes.

We also found at least some of what we were looking for. In Krill City, we collected the tiny larval (immature) krill that swarm under the ice bits (Fig. 5). These are the floating krill nurseries that contribute to the krill dense swarms of the Western Antarctic Peninsula region. The tiny krill feed on algae growing on the under-surface of the ice. We are particularly interested in the genetic make-up of these krill, which are a different generation from the juveniles and adults we have collected in other regions during our cruise.

Figure 5. Paola collecting larval krill from a floating “krill nursery” under a bit of ice.

The day in Flanders Bay was both thoroughly enjoyable and scientifically successful. For many of us, it was our favorite day of the cruise! It was also the last day of work for us. Later that night, we finished up our Salp Survey with a complete series of CTD cast, MOCNESS tow, and IKMT tow at the mouth of Flanders Bay. Then the technical team started breaking down our sampling gear and we steamed for our second port call at Palmer Station.